Wrench



May mi 1938. l T. M. HENDERSON 2,116,743

WRENCH Filed June 15, 1936 Patented May 10, 1938 PATENT OFFICE WRENCHThomas M. Henderson, Toronto, Ontario, Canada Application June 15, 1936,Serial No. 85,242

3 Claims.

This invention relates to wrenches ofthe adjustable jaw type andparticularly to pipe wrenches in which the outer jaw is the movable jawand carried by a stem slidable in a carrier casing supporting therelatively stationary jaw and carried by the shank or handle, and myobject is to devise a construction which is simple,

- reliable and durable and which can be quickly set to engage nuts,pipes or the like of any diameter within the range of the tool.

I attain my objects by means of constructions vwhich may be brieflydescribed as follows. The stem of the movable jaw slides freely in thecarrier casing and is provided with a nut threaded on the stem wherebyit may be adjusted to limit the extension of the stem.

The stationary jaw is rockable in the carrier casing by the shank whichhas a camming engagement with the underside of the jaw.

The stem of the movable jaw is pressed against the rear end of thecarrier casing by means of a removable leaf spring engaging the stem andtransverse abutment pins in the casing.

The invention is hereinafter more fully described and is illustrated inthe accompanying drawing in which Fig. 1 is a side elevation of thewrench, partly broken away;

Fig. 2 a similar view showing the wrench engaged with a pipe; and

Fig. 3 a section on the line 3-3 in Fig. 1.

In the drawing like numerals of reference indicate corresponding partsin the different iigures.

The wrench comprises three main portions, the handle or shank I, thecarrier casing 3, the inner jaw Il and the outer or movable jaw 6, whichis provided with a stem 'l slidable in the carrier casing. The stem 'lslides between the end of the carrier casing and the transverse wall orabutment t extending between opposite sides of the casing andlocatedadjacent the lower edge thereof. The inner end of the jaw 4 isengageable by the stem 'l' to prevent any but the smallest rockingmovement of the stem (see Fig. 2). The stem 'I of the movable jaw isthreaded and on it is screwed the nut 9, which, when the wrench is inoperation, abuts the lower edge of the casing 3. A stop I5 is secured tothe lower end of the stem 'I by means of a screw I 4, this stop beingintended to prevent the complete disengagement of the nut 9 from thestem l. The inner jaw 4 is pivoted in the carrier casing by means of thepivot pin 5. Adjacent the lower vedge of the casing the shank or handleI is pivoted by means of the pivot pin 2, which is preferably removablefor a purpose which will hereinafter appear. The upper end of the shankhas a camming engagement with the underside of the jaw 4 so that byrocking the handle or shank to the left, as indicated in the drawing,the inner jaw 4 will be rocked in the direction of the outer jaw 6. Theadjacent end of the carrier casing limits the rocking movement of theshank.

A spring I3, hereinafter more fully described, bearsagainst the side ofthe stem 'I to frictionally retain the stem in any position to which itis moved l The mode of operation is substantially as follows: If it isdesired to set the wrench to a pipe or other object to be embraced, thejaws are positioned about the object and the stem I slid in the casinguntil both jaws are engaged with the object. The nut 9 may then bequickly screwed up t0 engage the under side of the casing. Now as thewrench is turned by pressure on the shank I, the latter moves on itspivot to exert an outward pressure on the pivoted inner jaw Il 4byreason of `a camming engagement between the two. Obviously rocking theshank on its pivot will force the jaw l outwardly into a rm grippingrelation with the embraced object. This hinged mounting of the inner jawprevents the wrench from slipping, does away entirely with lost motionand avoids any rolling move# nient which might otherwise jamb the teethof the jaws on the pipe or other object gripped.

It will be noted that the nut bearing against the underside of thecasing provides a pivotal mounting for the movable jaw, which pivotalmovement is possible owing to the fact that the wall 8 extends onlypartly up from the underside of the carrier casing. The pivotal movementis, of course, quite small as only enough play is allowed to provide foran easy sliding movement of the stem.

The spring I3 is an important feature of my invention, its principalfunction being to frictionally hold the movable jaw in any position towhich it may be set until such time as the nut 9 is screwed up againstthe carrier casing. By positioning it between the inner jaw and the wall8 where it bears against the exposed inner side of the stem l, the stemis pressed evenly and n rmly against the end wall of the casing.

It is very desirable to avoid deformation or breakage of the spring thatbending of the spring during use should be reduced to a minimum and bypositioning it as shown this is attained since the rocking `movement ofthe stem 'I is Very small' due to the fact that it is the inner jaw thatrocks to give the wrench its grip and not the movable outer jaw. f

It is also important for assembly purposes and for voccasionalreplacement that the spring and other parts should be specially designedfor this purpose. The pivot 2 is therefore formed with a driving t inthe casing so that it may be readily removed when desired. Secured inthe carrier casing are the abutment pins I6 and I1. The spring I3 isV-shaped, the bend being preferably curved and tted about the pin I 6.The arm I 3a of the spring bears against the pin I1 and its end ispreferably curved to t partly around the pin to resist accidental upwarddisplacement of the spring. The arm I3 of the spring is preferablysomewhat curved to bear, adjacent its free end, against the stem 1.

When the pin 2 is removed the shank I is easily removed. The stop I5 isthen removed and the stem 'I removed from the casing. The spring I3 isthen readily introduced into the casing through the space left by theremoval of the -shank and may be readily tted over .the pin I6 and theend of its arm I3a engaged with the pin I'I. The stem I is then replacedand engages the arm I3b of the spring as hereinbefore described. y

From the above description it will be seen that I have devised a wrenchwhich is strong, durable, easily repaired, quickly adjustable, notliable to slip and which grips practically without lost motion.

What I claim as my invention is:

1. In a wrench, the combination of a carrier casing; an inner jawpivoted in the casing; a shank pivotally mounted in the casing andhaving a camming engagement with the inner jaw; a movable jaw providedwith a stem slidable in a guideway in the casing and having its innerside exposed the outer side of the guideway being substantially oneplane surface from end to end; a nut threaded on the stem outside thecasing; a leaf spring mounted in the casing between the shank and thestem and bearing against the exposed side of the stem; and abutments inthe casing against which the spring bears to exert pressure against thestem to press it frictionally against the plane outer side of itsguideway.

2. A wrench according to claim 1 in which the stem of the movable jawslides between an end of the carrier casing and a transverse wall in thecasing, the spring being located between the inner jaw and the saidwall.

3. In a wrench, the combination of a carrier casing; an `inner jawpivoted in the casing; a shank pivotally mounted in the casing andhaving a cammng engagement with the inner jaw; a movable jaw providedwith a stem slidable in a guideway in the casing and having its innerside exposed, the outer side of the guideway being substantially oneplane surface from end to end and its inner side formed by an abutmentformed inthe lower part of the casing and by the inner end of the innerjaw; a nut threaded on the stemoutside the casing; a leaf spring mountedin the casing between the shank and the stem and bearing against theexposed side of the stem; and abutments in the casing against which thespring bears to exert pressure against the stem to press it frictionallyagainst the plane outer side of its guideway.

THOMAS M. HENDERSON.

